On the 280z the turn signal flasher is directly above and to the right of the steering column; if I remember right it is mounted on a bracket just below the tachometer gauge. I had a signal light problem with my z too, but it the flasher was not the problem. The wire that feeds power to the flasher had broken somewhere along the circuit. I would defenetly check the flasher connector once it is found with a voltmeter to make sure it is getting power.